Method of rolling steel strip material



May 9, 1967 J. H. WERTHMAN 3,318,126

METHOD OF ROLLING STEEL STRIP MATERIAL Filed April 3, 1964 m 20 PIIS: 1

4 v Timer INVENTOI? JOHN H, WERTHMA/V AWor ey .maXimum elongation in aUnited States Patent Ofifice 3,318,125 Patented May 9, 1967 3,318,126METHOD OF ROLLING STEEL STRIP MATERIAL John H. Werthrnan, Leechburg,Pa., assignor to Allegheny Ludlum Steel Corporation, Brackenridge, Pa.,a corporation of Pennsylvania Filed Apr. 3, 1964, Ser. No. 357,148 12Claims. (Cl. 72-39) This invention relates to cold rolling of stripsteel, and more particularly to planish or temper rolling of steel stripmaterial having surface finishes.

The final rolling operation in the production of many grades of steel isa temper or planish roll. This temper rolling is for the purpose of coldworking the material to the proper hardness and strength, and also, inthe case of certain types of steel such as the ferritic grades ofstainless steel, serves the additional purpose of preventing theappearance of Liiders lines or stretcher strains when the material islater cold worked. To prevent the formation of stretcher strains orLiiders lines in ferritic stainless steel, it is necessary to cold workthe material in this temper rolling enough to provide an elongation ofat least about /8" in three feet of material or the cold work isinsufficient for this purpose. Since the rolls used for temper rollingare rather large in diameter, it is sometimes diificult to obtain thedesired elongation in a single pass, or even in two or three passes,especially in the case of rather thin material of the order of magnitudeof .008" to .012". It is well known that greater elongation can beobtained if wet rolling lubricants such as palm oil or soluble oils areused, but these lubricants will mark the surface of the steel beingrolled, detracting from its bright ness and appearance, and hence it iscommon practice to avoid the use of these rolling lubricants duringtemper rolling of bright surfaced material and to do the rolling dry(i.e., free of lubricants).

Also, when several passes are used to obtain the required elongation, itsometimes becomes a problem to maintain the strip completely fiat acrossits width, thus necessitating at least one or tWo additional flatteningpasses, all of which greatly increases the cost of finishing the strip.

It is therefore a principal object of this invention to provide a methodof temper rolling steel to provide the minimum number of passes withoutdamaging or marking the surface.

It is a further object of this invention to provide a method of temperrolling steel strip material, which rolling provides the elongationcharacteristics of rolling with a wet lubricant, yet which does not markor damage the surface of the steel.

Still a further, more particular object of this invention is theprovision of a method of rolling bright surfaced steel strip materialutilizing a film formed by the drying of a volatile substance, whichfilm enhances the elongation characteristics of the rolling withoutdetrimentally marking the surface of the material.

Still an additional object of this invention is the provision of amethod of rolling bright surfaced steel strip material wherein avolatile substance is sprayed on the rolls or on the material beingrolled, and is allowed to evaporate, leaving only a thin, invisible,adherent film when the material enters the bite of the rolls.

These and other objects, together with a fuller understanding of theinvention, will become apparent from the following description, whentaken in conjunction with the accompanying drawing in which:

FIGURE 1 is a schematic view of a temper rolling mill with the sprayingapparatus shown installed on the lower roll;

FlG. 2 is an enlarged view of the spraying apparatus, and i FIG. 3 is aview taken substantially along the line III-III of FIG. 2.

Referring now to the drawing, and in particular to FIG. 1, a two-hightemper mill is shown and designated generally as 10. The rolling mill 10is provided with an upper roll 12 and a lower roll 14 between which thematerial to be rolled, designated as M, is passed. In conventionaltemper rolling practice, these rolls 12 and 14 are maintained dry andfree of any rolling lubricant in order to avoid marking the surface ofthe strip as it is rolled. Any visible liquid which is on the surface ofthe material M as it enters the rolls, or which is on the rolls 12 or 14at the bite of the rolls where the material is entering, will mark thesurface of the strip.

According to this invention, a volatile substance such as methyl alcoholor other quick-drying alcohol, benzene, gasoline, etc., is placed eitheron the roll surfaces or on the surfaces of the strip or on both, thevolatile substance being allowed to evaporate to substantially completedryness, leaving only a very thin, invisible, tightly adherent film onthe surface of the roll or the material before the rolls and materialcome into contact with each other. As used herein, the term invisible isintended to denote that condition wherein all apparent wetness hasdisappeared. As shown in the drawing, the substance is sprayed onto therolls at an angle of about 270 prior to the contact of the rolls and thestrip by a series of upper spray heads 16 and lower spray heads 18. Theupper spray heads 16 spray the substance onto the upper roll 12, andlower spray heads 18 spray the substance onto the lower roll 14 in amanner that will be described presently. An upper wiper 20 made of feltor other suitable cloth or absorbent material is placed against theupper roll 12 and serves to spread the substance evenly on the roll, andalso to wipe off any excess. Similarly, a lower wiper 22 of felt orother suitable absorbent material is placed against the lower roll 14and serves to spread the substance evenly on the roll and also to wipeoff any excess. The rate of spraying of the substance is adjusted in amanner to be described presently such that the substance will havesubstantially completely evaporated .before the rolls contact thesurface of the material being rolled, and that remaining on the rollswill be only a very thin, invisible, tightly adherent film. This filmleft from the evaporation of the substance imparts to the rollingoperation the characteristics of rolling with a lubricant in thatsubstantially increased elongation occurs over that of dry rolling atthe same mill settings, but does not have the detrimentalcharacteristics of rolling with a lubricant in that it does not mark thesurface of the steel being rolled.

Although the drawing illustrates substance on both the top and bottomrolls and this is preferred, substantial benefit can also be derived byplacing the substance on either the top or the bottom roll alone. Also,instead of spraying the volatile substance on eitheror both of therolls, or in addition to spraying the rolls, it may 'be placed on thesurface of the strip at a location sufiiciently removed from the bite ofthe rolls that it will have evaporated, leaving only a thin, invisible,tightly adherent film before the strip enters the roll bite. A Wiperalso is desirable to spread the substance evenly on the strip surfaceand remove any excess.

Many volatile substances have been used to practice this invention,including those listed above. The only requirement is that the substancebe sufficiently volatile so that when it is applied to the roll or tothe strip, it will evaporate before the strip and roll come into contactat the bite of the rolls.

The spraying arrangement shown in the drawing is the preferred way ofgetting the volatile substance onto the the use of a volatile rolls, butother ways can also be used such as dripping the substance on or wipingit on with a saturated cloth, the only requirement being that it coverthe surface of the roll or the strip and that it be evaporated to athin, invisible, tightly adherent film before the material enters thebite of the rolls.

In the arrangement shown in the drawing, a spraying system is shownwhich includes a container 24 of the substance to be sprayed. Thecontainer is connected by a pipe 26 through a valve 28, a gauge 30,pressure regulator 32, and a filter 34 to a source of air supplydesignated generally as 36. The regulated air pressure delivers thesubstance from the container 24 through pairs of hoses 38 and 40 to eachof the spray heads 18 where it is sprayed onto the roll 14. A similarspraying system (not shown) is connected to the upper spray heads 16 ina similar manner. Such a spraying system is sold by the DeVilbissCompany, Toledo, Ohio, and is described in their parts list No. 48l0-A.The amount of spray delivered from the spray heads can be controlledeither by varying the head openings or the pressure, or by sprayingintermittently. The intermittent spraying may be accomplished byproviding a conventional timing device designated generally as 42, whichtiming device operates an electrical valve 44 between an open and closedposition, the timing device being adjustable to switch the valve betweenpositions at selected intervals of time, thereby causing an intermittentspray.

Although this invention has been shown and described with reference toparticular embodiments, various adaptations and modifications may bemade without departing from the scope and appended claims.

I claim:

1. In the method of temper rolling a steel strip member in a rollingmill having a pair of roll members, the improvement which comprises,placing a volatile substance on the surface of at least one of saidmembers, said substance being placed on at a location and in an amountsuch that it will have evaporated leaving only a tightly adherent, thin,invisible film at the bite of the rolls as the material is entering themill, and thereafter temper rolling the steel strip whereby said filmprovides increased elongation without detrimentally marking the surfaceof the strip.

2. The method of claim 1 wherein the substance is spread on the surfaceof the member by a wiper prior to evaporation.

3. The method of claim 1 wherein the volatile substance is a materialselected from the group consisting of alcohol, benzene, and gasoline.

4. In the method of temper rolling steel strip in a rolling mill havinga pair of rolls, the improvement which comprises, placing a volatilesubstance on the surface of at least one of said rolls, said substancebeing placed on at a location and in an amount such that it will haveevaporated leaving only a tightly adherent, thin, invisible film at thebite of the rolls as the material is entering the mill, and thereaftertemper rolling the steel strip whereby said film provides increasedelongation without detrimentally marking the surface of the strip.

5. In the method of temper rolling steel strip in a rolling mill havinga pair of rolls, the improvement which comprises, placing a volatilesubstance on at least one surface of said strip, said substance beingplaced on at a location and in an amount such that it will haveevaporated leaving only a tightly adherent, thin, invisible film at thebite of the rolls as the material is entering the mill, and thereaftertemper rolling the steel strip whereby said film provides increasedelongation without detrimentally marking the surface of the strip.

6. In the method of temper rolling steel strip in a rolling mill havinga pair of rolls, the improvement which comprises, spraying a volatilesubstance on the surface of at least one of said rolls, said substancebeing placed on at a location and in an amount such that it will haveevaporated leaving only a tightly adherent, thin, invisible film at thebite of the rolls as the material is entering the mill, and thereaftertemper rolling the steel strip whereby said film provides increasedelongation without detrimentally marking the surface of the strip.

7. The methodof claim 6 wherein the substance is spread by a wiper overthe surface of the roll prior to its evaporation.

8. In the method of temper rolling a steel strip member in a rollingmill having a pair of roll members, the improvement which comprises,spraying a volatile substance on the surface of at least one of saidmembers, said substance being placed on at a location and in an amountsuch that it will be evaporated leaving only a tightly adherent, thin,invisible film at the bite of the rolls as the material is entering themill, spreading the substance by means of a Wiper over the surface onwhich it is sprayed prior to its evaporation, and thereafter temperrolling the steel strip whereby said film provides increased elongationwithout detrimentally marking the surface of the strip.

9. In the method of temper rolling a steel strip member in a rollingmill having a pair of roll members, the improvement which comprises,spraying methyl alcohol on the surface of at least one of said members,said alcohol being placed on at a location and in an amount such that itwill have evaporated to substantial dryness leaving only a tightlyadherent, thin, invisible film at the bite of the rolls as the materialis entering the mill, and thereafter temper rolling the steel stripwhereby said film provides increased elongation without detrimentallymarking the surface of the strip.

10. The method of claim 9 wherein the sprayed onto at least one rollmember.

11. The method of claim 9 wherein the sprayed onto the surface of thestrip member.

12. The method of claim 9 wherein the alcohol is spread over the surfaceby a wiper prior to its evaporation.

alcohol is alcohol is References Cited by the Examiner UNITED STATESPATENTS 2,258,930 10/1941 Haefner 7242 2,659,252 11/1953 Kipp 72-42CHARLES W. LANHAM, Primary Examiner.

H. DIETER HOINKES, Assistant Examiner.

1. IN THE METHOD OF TEMPER ROLLING A STEEL STRIP MEMBER IN A ROLLINGMILL HAVING A PAIR OF ROLL MEMBERS, THE IMPROVEMENT WHICH COMPRISES,PLACING A VOLATILE SUBSTANCE ON THE SURFACE OF AT LEAST ONE OF SAIDMEMBERS, SAID SUBSTANCE BEING PLACED ON AT A LOCATION AND IN AN AMOUNTSUCH THAT IT WILL HAVE EVAPORATED LEAVING ONLY A TIGHTLY ADHERENT, THIN,INVISIBLE FILM AT THE BITE OF THE ROLLS AS THE MATERIAL IS ENTERING THEMILL, AND THEREAFTER TEMPER ROLLING THE STEEL STRIP WHEREBY SAID FILMPROVIDES INCREASED ELONGATION WITHOUT DETRIMENTALLY MARKING THE SURFACEOF THE STRIP.